In a California eviction, service by posting in an unlawful detainer case is a last-resort way to notify a tenant about the lawsuit: the Summons and Complaint are physically attached to the rental property and a copy is mailed by certified mail, but only after a judge signs an order finding that personal and substituted service failed despite reasonable diligence. The method is governed by California Code of Civil Procedure Section 415.45, and the statute is scheduled to be repealed on January 1, 2027, unless the Legislature extends it.1California Legislative Information. California Code of Civil Procedure 415.45
What Must Be Tried Before Posting
A court will not authorize posting until the landlord shows, by affidavit, that the tenant “cannot with reasonable diligence be served in any manner specified in this article other than publication.”2Justia Law. California Code of Civil Procedure 415.45 Two methods have to be tried and documented first.
Personal service means physically handing the Summons and Complaint to the tenant. If the server cannot find the tenant after multiple attempts, the next step is substituted service: leaving the papers with a competent adult at least 18 years old at the tenant’s home or workplace, telling that person what the papers are, and mailing a copy by first-class mail to the same address.3California Legislative Information. California Code of Civil Procedure CCP 415.20 Substituted service is complete on the tenth day after mailing. Only when both methods have genuinely failed is posting on the table.
What Reasonable Diligence Looks Like
The statute does not set a magic number of attempts, but judges expect the process server’s log to show visits on different days and at different times. Three attempts all at 2:00 p.m. on a weekday are not going to convince a court. Mornings, evenings, and weekends together show a real effort to catch the tenant at home.
The declaration of diligence should go beyond dates and times. Each entry should note what the server observed: lights on or off, cars in the driveway, anything a neighbor or property manager said about the tenant’s schedule. If a neighbor mentions night shifts, the next attempt should be during the day. These details tell the judge the server investigated rather than ran through the motions.
The landlord submits this evidence by ex parte application, with the server’s declaration signed under penalty of perjury. If the judge finds the diligence insufficient, the application is denied and the landlord has to make more attempts before asking again.
Who Can Post and Mail
Service must be carried out by someone who is at least 18 years old and not a party to the lawsuit, which rules out the landlord doing it personally.4California Legislative Information. California Code of Civil Procedure 414.10 Most landlords use a registered process server or the county sheriff. Whoever performs the service signs the proof of service under penalty of perjury, so experience with the requirements matters.
How the Posting and Mailing Are Carried Out
Once the judge signs the order, two things happen. The Summons and Complaint are affixed to the property “in a manner most likely to give actual notice,” which usually means the front door unless the order specifies another conspicuous location. A copy is then mailed by certified mail to the tenant’s last known address, almost always the rental itself.1California Legislative Information. California Code of Civil Procedure 415.45
The statute says the mailing must happen “forthwith” after the order, meaning promptly and without unnecessary delay. The statute does not say “same day,” but any gap invites a challenge, so posting and mailing on the day the order is signed is the safest route.
Filing the Proof of Service
After posting and mailing, the server completes and files the Proof of Service of Summons, Judicial Council Form POS-010.5California Courts. Proof of Service of Summons The form records the exact date of posting, where the documents were affixed, the date of the certified mailing, and the address used. It must also reference the court order that authorized posting. Without that reference, the court has no way to confirm the service was authorized at all, and the service can be thrown out no matter how carefully the physical steps were performed. The server signs under penalty of perjury, and once the form is filed with the clerk, the tenant’s response clock begins.
When Service Is Complete and When the Tenant Must Answer
Service by posting is not immediately effective. It is deemed complete on the tenth calendar day after both the posting and the mailing have occurred.1California Legislative Information. California Code of Civil Procedure 415.45 That window gives the mailed copy time to reach the tenant.
Once service is deemed complete, the tenant has 10 days to file an Answer on Judicial Council Form UD-105 or another responsive pleading.6California Legislative Information. California Code of Civil Procedure 11677California Courts. Answer – Unlawful Detainer Those 10 days exclude Saturdays, Sundays, and judicial holidays, so the actual calendar time is often closer to two weeks. California observes more court holidays than the federal calendar, and each one that falls inside the response window pushes the deadline out another day. Miscounting the deadline is one of the most common mistakes in unlawful detainer cases.
The Military Affidavit Before Default Judgment
If the tenant does not respond, the landlord will usually seek a default judgment. Before the court enters one, federal law requires the landlord to file an affidavit stating whether the tenant is on active military duty or that the landlord could not determine the tenant’s military status.8Office of the Law Revision Counsel. 50 USC 3931 – Protection of Servicemembers Against Default Judgments The requirement comes from the Servicemembers Civil Relief Act and applies to every civil default judgment in the country, California evictions included.
If the tenant is an active-duty servicemember, the court cannot enter default until it appoints an attorney for the absent tenant. If military status cannot be determined, the court may require a bond to protect the tenant against losses if the judgment is later overturned. Skipping the affidavit does not just risk delay; it makes the default judgment voidable.
What Happens When Posting Is Defective
Defective service in an unlawful detainer case is not a technicality courts overlook. If a tenant discovers a default judgment was entered without proper notice, they can move to set aside the default under CCP 473.5. The tenant has to show that the lack of actual notice was not caused by their own avoidance of service or by inexcusable neglect.9California Legislative Information. California Code of Civil Procedure CCP 473.5
The motion must be filed within a reasonable time, and no later than two years after entry of the default judgment or 180 days after the tenant receives written notice that the default was entered, whichever comes first.9California Legislative Information. California Code of Civil Procedure CCP 473.5 If the motion is granted, the judgment is set aside and the case starts over.
Common defects that trigger these challenges include posting before obtaining the court order, posting in a location that is not conspicuous, mailing to an address other than the tenant’s last known address, and filing a proof of service that does not reference the authorizing order. Any one of these can invalidate the service on its own.
The 2027 Sunset on Section 415.45
Section 415.45 is scheduled to be repealed on January 1, 2027, unless the Legislature extends it.1California Legislative Information. California Code of Civil Procedure 415.45 The provision has been renewed before, but renewal is not guaranteed. Anyone planning an unlawful detainer action near the end of 2026 should confirm the statute is still in effect before relying on posting. If it lapses without a replacement, landlords who cannot achieve personal or substituted service would be left with service by publication, which is slower and carries its own requirements.